The interior heating of my Modus is very weak, The level is

Customer Question

The interior heating of my Modus is very weakJA: Have you checked the coolant level? Has there been any leaking from the hoses?Customer: The level is ok, but there was a leak in the radiator some time ago and it was fixed by adding some stuff in the coolant. After that the coolant was replaced so could it be that there is an airlock somewhereJA: What is the model/year of your Renault?Customer: It's 2005 Modus with 1.4 l petrol engineJA: Are you fixing your vehicle yourself? What have you tried so far?Customer: Yes, I'm fixing it myself. I have only tried to bleed the air form the system by manually opening the bleeding vent (I think there two of them)JA: Anything else you want the mechanic to know before I connect you?Customer: The other possibility might be that the stuff added to the coolant has

Hello,Yes, the engine reaches normal temperature and stays there. And the engine was ran to full temperature without the cap.But when I replaced the coolant, I didn't find the bleeding vents. Only much later I try to bleed the system by opening those while engine was running warm. Could it be that there is an airlock somewhere? I have planing to drain the system and refill it more correctly with the bleeding vents open. What do you think?